[Samba] SIDs and UIDs and RIDs - Oh My!

[Jeremy Allison]

On Sat, Aug 13, 2005 at 05:00:16PM -0700, Moondance Foxmarnick wrote:
> 
> But what the @$@! is a Relative IDentifier (RID)?!?
> 
> On page 153 the command to map a windows group to a *nix group - no mention
> of RIDs.

A SID is a 128 bit identifier of a user/group/computer on a network
(a GUUID really). It consists of a 96-bit "domain" id, with a 32-bit
"relative id" (RID) suffix.

So for a given RID, you prepend the 96-bit domain id to get the full
SID.

SIDs are supposed to be "structured", but for real users/groups
and computers they are of the form described above.

Certain (less than 128 bit) SIDs are "well known" SIDs. Such as
the "Administrators" group.

Jeremy.